Srv2/CAP is required for polarized actin cable assembly and patch internalization during clathrin-mediated endocytosis

Toshima, Junko Y.; Horikomi, Chika; Okada, Asuka; Hatori, Makiko N.; Nagano, Makoto; Masuda, Akira; Yamamoto, Wataru; Siekhaus, Daria E; Toshima, Jiro

doi:10.1242/jcs.176651

Cited by 9 publications

(9 citation statements)

References 48 publications

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“…The movement of this Pan1p/actin aggregate in pan1-18TA was sensitive to SMIFH2 but not CK-666, suggesting that the aberrant structure associates with actin cables ( Figure 4—figure supplement 1B–E ). In a recent study, we showed that ~85% of endocytic vesicles were internalized along actin cables at the internalization step of endocytosis ( Toshima et al, 2015 ). Here we show that in this step, Pan1-mCherry-labeled vesicles in wild-type cells associated with actin cables for ~4.6 s and moved on cables about 0.4 μm after internalization ( Figure 4A,B,C ).…”

Section: Resultsmentioning

confidence: 99%

Yeast Eps15-like endocytic protein Pan1p regulates the interaction between endocytic vesicles, endosomes and the actin cytoskeleton

Toshima

Furuya

Nagano

et al. 2016

eLife

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The actin cytoskeleton plays important roles in the formation and internalization of endocytic vesicles. In yeast, endocytic vesicles move towards early endosomes along actin cables, however, the molecular machinery regulating interaction between endocytic vesicles and actin cables is poorly understood. The Eps15-like protein Pan1p plays a key role in actin-mediated endocytosis and is negatively regulated by Ark1 and Prk1 kinases. Here we show that pan1 mutated to prevent phosphorylation at all 18 threonines, pan1-18TA, displayed almost the same endocytic defect as ark1Δ prk1Δ cells, and contained abnormal actin concentrations including several endocytic compartments. Early endosomes were highly localized in the actin concentrations and displayed movement along actin cables. The dephosphorylated form of Pan1p also caused stable associations between endocytic vesicles and actin cables, and between endocytic vesicles and endosomes. Thus Pan1 phosphorylation is part of a novel mechanism that regulates endocytic compartment interactions with each other and with actin cables.DOI: http://dx.doi.org/10.7554/eLife.10276.001

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Section: Resultsmentioning

confidence: 99%

Yeast Eps15-like endocytic protein Pan1p regulates the interaction between endocytic vesicles, endosomes and the actin cytoskeleton

Toshima

Furuya

Nagano

et al. 2016

eLife

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“…It has been reported that CAP protein interacts directly with V-ATPase and acts as a general regulator of endocytosis in Dictyostelium (Sultana et al, 2005). A recent study has shown that Srv2/Cap1 is responsible for efficient endocytosis by aiding initial vesicle invagination and movement (Toshima et al, 2016). Some of the defects observed in the Fgcap1 mutant may be independent of cAMP signalling, but related to the role of FgCAP1 in endocytosis in F. graminearum.…”

Section: Discussionmentioning

confidence: 99%

The cyclase‐associated protein FgCap1 has both protein kinase A‐dependent and ‐independent functions during deoxynivalenol production and plant infection in Fusarium graminearum

Yin

Zhang

Wang

et al. 2017

Molecular Plant Pathology

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Fusarium graminearum is a causal agent of wheat scab and a producer of the trichothecene mycotoxin deoxynivalenol (DON). The expression of trichothecene biosynthesis (TRI) genes and DON production are mainly regulated by the cyclic adenosine monophosphate-protein kinase A (cAMP-PKA) pathway and two pathway-specific transcription factors (TRI6 and TRI10). Interestingly, deletion mutants of TRI6 show reduced expression of several components of cAMP signalling, including the FgCAP1 adenylate-binding protein gene that has not been functionally characterized in F. graminearum. In this study, we show that FgCap1 interacts with Fac1 adenylate cyclase and that deletion of FgCAP1 reduces the intracellular cAMP level and PKA activity. The Fgcap1 deletion mutant is defective in vegetative growth, conidiogenesis and plant infection. It also shows significantly reduced DON production and TRI gene expression, which can be suppressed by exogenous cAMP, indicating a PKA-dependent regulation of DON biosynthesis by FgCap1. The wild-type, but not tri6 mutant, shows increased levels of intracellular cAMP and FgCAP1 expression under DON-producing conditions. Furthermore, the promoter of FgCAP1 contains one putative Tri6-binding site that is important for its function during DON biosynthesis, but is dispensable for hyphal growth, conidiogenesis and pathogenesis. In addition, FgCap1 shows an actin-like localization to the cortical patches at the apical region of hyphal tips. Phosphorylation of FgCap1 at S353 was identified by phosphoproteomics analysis. The S353A mutation in FgCAP1 has no effect on its functions during vegetative growth, conidiation and DON production. However, expression of the FgCAP1 allele fails to complement the defects of the Fgcap1 mutant in plant infection, indicating the importance of the phosphorylation of FgCap1 at S353 during pathogenesis. Taken together, our results suggest that FgCAP1 is involved in the regulation of DON production via cAMP signalling and subjected to a feedback regulation by TRI6, but the phosphorylation of FgCap1 at S353 is probably unrelated to the cAMP-PKA pathway because the S353A mutation only affects plant infection.

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“…Srv2 was previously known to regulate actin recycling and severing. Both polarized actin cable assembly and patch formation are the major regulatory functions of Srv2/CAP (Toshima et al., 2016). Our results of SRV2 deletion and mutant alleles bring the regulatory mechanisms of mitochondria and actin dynamics together.…”

Section: Discussionmentioning

confidence: 99%

Srv2 Is a Pro-fission Factor that Modulates Yeast Mitochondrial Morphology and Respiration by Regulating Actin Assembly

Chen

Cheng²,

Lin

et al. 2019

iScience

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SummaryDynamic processes such as fusion, fission, and trafficking are important in the regulation of cellular organelles, with an abundant literature focused on mitochondria. Mitochondrial dynamics not only help shape its network within cells but also are involved in the modulation of respiration and integrity. Disruptions of mitochondrial dynamics are associated with neurodegenerative disorders. Although proteins that directly bind mitochondria to promote membrane fusion/fission have been studied intensively, machineries that regulate dynamic mitochondrial processes remain to be explored. We have identified an interaction between the mitochondrial fission GTPase Dnm1/DRP1 and the actin-regulatory protein Srv2/CAP at mitochondria. Deletion of Srv2 causes elongated-hyperfused mitochondria and reduces the reserved respiration capacity in yeast cells. Our results further demonstrate that the irregular network morphology in Δsrv2 cells derives from disrupted actin assembly at mitochondria. We suggest that Srv2 functions as a pro-fission factor in shaping mitochondrial dynamics and regulating activity through its actin-regulatory effects.

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Srv2/CAP is required for polarized actin cable assembly and patch internalization during clathrin-mediated endocytosis

Cited by 9 publications

References 48 publications

Yeast Eps15-like endocytic protein Pan1p regulates the interaction between endocytic vesicles, endosomes and the actin cytoskeleton

Yeast Eps15-like endocytic protein Pan1p regulates the interaction between endocytic vesicles, endosomes and the actin cytoskeleton

The cyclase‐associated protein FgCap1 has both protein kinase A‐dependent and ‐independent functions during deoxynivalenol production and plant infection in Fusarium graminearum

Srv2 Is a Pro-fission Factor that Modulates Yeast Mitochondrial Morphology and Respiration by Regulating Actin Assembly

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